This invention relates to a swirling burner for use in a stove in connection with a blast furnace the stove being, for example, connected with the blast furnace.
In a blast furnace, for the purpose of storing heat it is usual to burn fuel in the combustion chamber by using a burner and to store the heat of combustion in a heat accumulating chamber connected to the combustion chamber. Among prior burners utilized with such blast furnaces are included a type wherein air and fuel gas are blown into the combustion chamber through rotary blades, thereby rotating the air and fuel gas mixture for burning it rapidly; and a type wherein a ceramic grill is disposed above blow heads for blowing air and fuel gas and provided at the bottom of the combustion chamber, thus ejecting the air-fuel mixture straight upwardly and causing it to burn. These prior art burners have advantages and defects as follows. More particularly, the recent tendency of increasing the capacity of the blast furnace and development in the art of high temperature air supply requires combustion under a high load. With the burner using rotary blades, an oscillatory combustion occurs when the flow quantity is increased so that this type of burner is not suitable for high load combustion using a large quantity of fuel gas. Although the burner using a grill is free from such defects since the air and fuel gas as ejected upwardly from the burner as parallel streams, they are not sufficiently mixed together with the result that the flame extends too long or after burning occurs due to entrance of the not burned fuel gas into the heat accumulating chamber. This causes local abnormal heating of the heat accumulating chamber and damage and disintegration of gitter bricks. Consequently, the pressure loss increases abnormally which causes decrease in the quantity of gas combustion. Moreover, the length of the flame is greatly influenced by the change in the percentage of excess air. These phenomena make it difficult to maintain a stable combustion state.